Dr. Robert Kohn is a longtime Providence, Rhode Island geriatric psychiatrist who has worked extensively with homebound elders. As an Md, one area of research focus for Dr. Robert Kohn has been understanding psychosocial stressors and psychiatric resilience among survivors of disaster.

A key aspect of this topic is understanding the difference between manageable and traumatic stressors. Typically of less severity, manageable stressors are those that allow people to employ coping strategies that help lower the stress level.

The inoculation hypothesis posits that manageable stressors provide a template for coping with later stressful occurrences. For example, coping with unemployment once provides direct tolerance, or the ability to cope with a future period of unemployment. Unemployment can also provide cross tolerance, or a form of inoculation that applies to a different future stressor, such as a divorce. Thus, one positive impact of manageable stress is in providing inoculation against stress-related disorders such as major depressive disorder (MDD) and PTSD.

By contrast, traumatic stressors such as those experienced in combat, have a more extreme manifestation and may overwhelm the ability of the individual to effectively cope. The emotional distress engendered is beyond the ability of the person to independently manage, with the stress response system exhausted. Prior unmanageable and traumatic stressors seem to increase the likelihood of psychiatric disorders such as MDD and PTSD occurring later in life.